Copy the KDE 3.5 branch to branches/trinity for new KDE 3.5 features.

BUG:215923


git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdenetwork@1054174 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

1 files changed, 433 insertions, 0 deletions

diff --git a/krdc/smartptr.h b/krdc/smartptr.h
new file mode 100644
index 00000000..d80f258e
--- /dev/null
+++ b/krdc/smartptr.h
@@ -0,0 +1,433 @@
+/***************************************************************************
+    begin                : Wed Jan 1 17:56 CET 2003
+    copyright            : (C) 2003 by Tim Jansen
+    email                : [email protected]
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef SMARTPTR_H
+#define SMARTPTR_H
+
+#include <qstring.h>
+
+class WeakPtr;
+
+/**
+ * @internal
+ */
+struct SmartPtrRefCount {
+	SmartPtrRefCount(int toObj, int toThis) :
+		refsToObject(toObj),
+	        refsToThis(toThis) {
+	}
+	int refsToObject; // number of pointers to the object, 0 if released
+	int refsToThis;   // number of pointer to the ref count
+};
+
+/**
+ * SmartPtr is a reference counting smart pointer. When you create
+ * the first instance it will create a new counter for the pointee
+ * and it share it with all other SmartPtr instances for that pointee.
+ * The reference count can only be kept accurate when you do not create
+ * a second 'realm' of references by converting a SmartPtr into a
+ * regular pointer and then create a new SmartPtr from that pointer.
+ * When the last instance of a SmartPtr for the given object has been
+ * deleted the object itself will be deleted. You can stop the SmartPtr
+ * system to manage an object by calling @ref release() on any of
+ * the pointers pointing to that object. All SmartPtrs will then stop
+ * managing the object, and you can also safely create a second 'realm'.
+ *
+ * SmartPtr can be combined with @ref WeakPtr. A WeakPtr
+ * does not influence its life cycle, but notices when a SmartPtr
+ * deletes the object.
+ *
+ * The recommended way to use SmartPtr and @ref WeakPtr is to use SmartPtr
+ * for all aggregations and WeakPtr for associations. Unlike auto_ptr, 
+ * SmartPtr can be used in collections.
+ *
+ * SmartPtr is not thread-safe. All instances of SmartPtrs pointing
+ * to a pointee must always be in the same thread, unless you break
+ * the 'realm' by calling @ref release() in one thread and give the
+ * original pointer the other thread. It can then create a new SmartPtr
+ * and control the lifecycle of the object.
+ * @see WeakPtr
+ */
+template <class T> 
+class SmartPtr
+{
+ public: // members are public because of problems with gcc 3.2
+	friend class WeakPtr;
+
+  /// @internal
+	T* ptr;
+  /// @internal
+	mutable SmartPtrRefCount *rc; // if !rc, refcount=1 is assumed
+
+protected:
+	void freePtr() {
+		if (!ptr)
+			return;
+		if (!rc)
+			delete ptr;
+		else {
+			if (rc->refsToObject > 0) {
+				Q_ASSERT(rc->refsToObject >= rc->refsToThis);
+				if (rc->refsToObject == 1) {
+					delete ptr;
+					rc->refsToObject = -1;
+				}
+				else
+					rc->refsToObject--;
+			}
+			rc->refsToThis--;
+			if (rc->refsToThis < 1)
+				delete rc;
+		}
+	}
+	
+	void init(T *sptr, SmartPtrRefCount *&orc)
+	{
+		ptr = sptr;
+		if (!sptr)
+			rc = 0;
+		else if (!orc) {
+			orc = new SmartPtrRefCount(2, 2);
+			rc = orc;
+		}
+		else {
+			rc = orc;
+			rc->refsToThis++;
+			if (rc->refsToObject) {
+				// prevent initialization from invalid WeakPtr
+				Q_ASSERT(rc->refsToObject > 0);
+				rc->refsToObject++;
+			}
+		}
+	}
+	
+	SmartPtr(T *p, SmartPtrRefCount *&orc)
+	{
+		init(p, orc);
+	}
+
+public:
+	/**
+	 * Creates a SmartPtr that refers to the given pointer @p.
+	 * SmartPtr will take control over the object and delete it
+	 * when the last SmartPtr that referes to the object
+	 * has been deleted.
+	 * @param p the pointer to the object to manage, or the null pointer
+	 */
+	SmartPtr(T* p = 0) :
+		ptr(p),
+		rc(0)
+	{
+	}
+	
+	/**
+	 * Copies the given SmartPtr, sharing ownership with the other
+	 * pointer. Increases the reference count by 1 (if the object
+	 * has not been @ref release()d).
+	 * @param sptr the object pointer to copy
+	 */
+	SmartPtr(const SmartPtr<T> &sptr) 
+	{
+		init(sptr.ptr, sptr.rc);
+	}
+
+	/**
+	 * Copies the given SmartPtr, sharing ownership with the other
+	 * pointer. Increases the reference count by 1 (if the object
+	 * has not been @ref release()d).
+	 * @param sptr the object pointer to copy
+	 */
+	template<class T2>
+	SmartPtr(const SmartPtr<T2> &sptr) 
+	{
+		init((T*)sptr.ptr, sptr.rc);
+	}
+
+	/**
+	 * Delete the pointer and, if the reference count is one and the object has not
+	 * been released, deletes the object. 
+	 */
+	~SmartPtr() {
+		freePtr();
+	}
+
+	/**
+	 * Copies the given SmartPtr, sharing ownership with the other
+	 * pointer. Increases the reference count by 1 (if the object
+	 * has not been @ref release()d). The original object will be dereferenced
+	 * and thus deleted, if the reference count is 1.
+	 * @param sptr the object pointer to copy
+	 * @return this SmartPtr object
+	 */
+	SmartPtr &operator=(const SmartPtr<T> &sptr) {
+		if (this == &sptr)
+			return *this;
+
+		freePtr();
+		init(sptr.ptr, sptr.rc);
+		return *this;
+	}
+
+	/**
+	 * Copies the given SmartPtr, sharing ownership with the other
+	 * pointer. Increases the reference count by 1 (if the object
+	 * has not been @ref release()d). The original object will be dereferenced
+	 * and thus deleted, if the reference count is 1.
+	 * @param sptr the object pointer to copy
+	 * @return this SmartPtr object
+	 */
+	template<class T2>
+	SmartPtr &operator=(const SmartPtr<T2> &sptr) {
+		if (this == static_cast<SmartPtr<T> >(&sptr))
+			return *this;
+
+		freePtr();
+		init(static_cast<T>(sptr.ptr), sptr.rc);
+		return *this;
+	}
+
+	/**
+	 * Sets the SmartPointer to the given value. The original object
+	 * will be dereferenced and thus deleted, if the reference count is 1.
+	 * @param p the value of the new pointer
+	 */
+	void set(T *p) {
+		if (ptr == p)
+			return;
+		freePtr();
+		
+		ptr = p;
+		rc = 0;
+	}
+
+	/**
+	 * Releases the ptr. This means it will not be memory-managed 
+	 * anymore, neither by this SmartPtr nor by any other pointer that
+	 * shares the object. The caller is responsible for freeing the 
+	 * object. It is possible to assign the plain pointer (but not the 
+	 * SmartPtr!) to another SmartPtr that will then start memory
+	 * management. This may be useful, for example, to let another
+	 * thread manage the lifecyle.
+	 * @return the pointer, must be freed by the user
+	 * @see data()
+	 */
+	T* release() {
+		if (!rc)
+			rc = new SmartPtrRefCount(0, 1);
+		else
+			rc->refsToObject = 0;
+		return ptr;
+	}
+
+	/**
+	 * Sets the SmartPointer to the given value. The original object
+ 	 * will be dereferenced and thus deleted, if the reference count is 1.
+	 * @param p the value of the new pointer
+	 * @return this SmartPtr object
+	 */
+	SmartPtr &operator=(T *p) {
+		set(p);
+		return *this;
+	}
+
+        /**
+         * Returns true if the SmartPtr points to an actual object, false
+         * if it is the null pointer.
+         * @return true for an actual pointer, false for the null pointer
+         */
+        operator bool() const {
+                return ptr != 0;
+        }
+
+        /**
+         * Returns the plain pointer to the pointed object. The object will
+         * still be managed by the SmartPtr. You must ensure that the pointer
+         * is valid (so don't delete the SmartPtr before you are done with the
+         * plain pointer).
+         * @return the plain pointer
+         * @see data()
+         * @see release()
+         * @see WeakPtr
+         */
+	template<class T2>
+	operator T2*() const { 
+		return static_cast<T2*>(ptr);
+	}
+
+        /**
+         * Returns the plain pointer to the pointed object. The object will
+         * still be managed by the SmartPtr. You must ensure that the pointer
+         * is valid (so don't delete the SmartPtr before you are done with the
+         * plain pointer).
+         * @return the plain pointer
+         * @see data()
+         * @see release()
+         * @see WeakPtr
+         */
+	template<class T2>
+	operator const T2*() const { 
+		return static_cast<const T2*>(ptr);
+	}
+
+        /**
+         * Returns a reference to the pointed object. This works exactly
+         * like on a regular pointer.
+         * @return the pointer object
+         */
+	T& operator*() {
+		return *ptr;
+	}
+
+        /**
+         * Returns a reference to the pointed object. This works exactly
+         * like on a regular pointer.
+         * @return the pointer object
+         */
+	const T& operator*() const {
+		return *ptr;
+	}
+
+        /**
+         * Access a member of the pointed object. This works exactly
+         * like on a regular pointer.
+         * @return the pointer
+         */
+	T* operator->() {
+		return ptr;
+	}
+
+        /**
+         * Access a member of the pointed object. This works exactly
+         * like on a regular pointer.
+         * @return the pointer
+         */
+	const T* operator->() const {
+		return ptr;
+	}
+
+        /**
+         * Compares two SmartPtrs. They are equal if both point to the
+         * same object.
+         * @return true if both point to the same object
+         */
+	bool operator==(const SmartPtr<T>& sptr) const { 
+		return ptr == sptr.ptr; 
+	}
+
+        /**
+         * Compares two SmartPtrs. They are unequal if both point to
+         * different objects.
+         * @return true if both point to different objects
+         */
+	bool operator!=(const SmartPtr<T>& sptr) const {
+		return ptr != sptr.ptr;
+	}
+ 
+        /**
+         * Compares a SmartPtr with a plain pointer. They are equal if
+         * both point to the same object.
+         * @return true if both point to the same object
+         */
+	bool operator==(const T* p) const {
+		return ptr == p;
+	}
+
+        /**
+         * Compares a SmartPtr with a plain pointer. They are unequal if
+         * both point to different objects.
+         * @return true if both point to different objects
+         */
+	bool operator!=(const T* p) const {
+		return ptr != p;
+	}
+
+        /** 
+         * Negates the pointer. True if the pointer is the null pointer
+         * @return true for the null pointer, false otherwise
+         */
+	bool operator!() const {
+		return ptr == 0;
+	}
+
+        /**
+         * Returns the pointer. The object will still be managed
+         * by the SmartPtr. You must ensure that the pointer
+         * is valid (so don't delete the SmartPtr before you are done with the
+         * plain pointer).
+         * @return the plain pointer
+         * @see release()
+         * @see WeakPtr
+         */ 
+	T* data() { 
+		return ptr; 
+	}
+	
+        /**
+         * Returns the pointer. The object will still be managed
+         * by the SmartPtr. You must ensure that the pointer
+         * is valid (so don't delete the SmartPtr before you are done with the
+         * plain pointer).
+         * @return the plain pointer
+         * @see release()
+         * @see WeakPtr
+         */ 
+	const T* data() const { 
+		return ptr; 
+	}
+
+	/**
+	 * Checks whether both SmartPtrs use the same pointer but two
+	 * different reference counts.
+	 * If yes, one of them must be 0 (object released), otherwise 
+	 * it is an error.
+	 * @return true if the pointers are used correctly
+	 */
+	bool isRCCorrect(const SmartPtr<T> &p2) const {
+		if (ptr == p2.ptr)
+			return true;
+		if (rc == p2.rc)
+			return true;
+		return (rc->refsToObject == 0) || (p2.rc->refsToObject == 0);
+	}
+
+	/**
+	 * Returns the reference count of the object. The count is 0 if
+	 * the object has been released (@ref release()). For the null pointer
+	 * the reference count is always 1.
+	 * @return the reference count, or 0 for released objects
+	 */
+	int referenceCount() const {
+		return rc ? rc->refsToObject : 1;
+	}
+
+	/**
+	 * Returns a string representation of the pointer.
+	 * @return a string representation
+	 */
+	QString toString() const {
+		int objrcount = 1;
+		int rcrcount = 0;
+
+		if (rc) {
+			objrcount = rc->refsToObject;
+			rcrcount = rc->refsToThis;
+		}
+		return QString("SmartPtr: ptr=%1, refcounts=%2, ptrnum=%3")
+			.arg((int)ptr).arg(objrcount).arg(rcrcount);
+	}
+
+};
+
+#endif